[PATCH 4.9 010/120] drm/savage: dereferencing an error pointer

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

commit f7741aa75e76440f4e9ecfe512feebe9bce33ca8 upstream.

A recent cleanup changed the kmalloc() + copy_from_user() to
memdup_user() but the error handling wasn't updated so we might call
kfree(-EFAULT) and crash.

Fixes: a6e3918bcdb1 ('GPU-DRM-Savage: Use memdup_user() rather than duplicating')
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
Link: http://patchwork.freedesktop.org/patch/msgid/20161012062227.GU12841@mwanda
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/gpu/drm/savage/savage_state.c |    1 +
 1 file changed, 1 insertion(+)

--- a/drivers/gpu/drm/savage/savage_state.c
+++ b/drivers/gpu/drm/savage/savage_state.c
@@ -1004,6 +1004,7 @@ int savage_bci_cmdbuf(struct drm_device
 		kvb_addr = memdup_user(cmdbuf->vb_addr, cmdbuf->vb_size);
 		if (IS_ERR(kvb_addr)) {
 			ret = PTR_ERR(kvb_addr);
+			kvb_addr = NULL;
 			goto done;
 		}
 		cmdbuf->vb_addr = kvb_addr;